Trying to use my old 2011 Mac High Sierra as a monitor for 2017 MacBook Air Monterey with thunderbolt cable. Can’t seem to get it to work.
Any ideas?
it does not work with Monterey (macOS 12.7.6) "macOS Catalina (macOS 10.15.7) or earlier installed"
from
Use your iMac as a display with target display mode - Apple Support
You cannot install an older version of macOS (Catalina) "in place" over top of a newer one (Monterey). You will need to do a "clean install."
Migrating things like Photo and Music libraries back may be "interesting" if Apple changed their format between Catalina and Monterey.
Catalna's version of Safari is older than Monterey's version - and current versions of many third-party browsers now require Monterey or better. The current version of Firefox still runs on Catalina, but who knows for how long?
It probably makes sense to "bite the bullet" and buy a real external display instead of putting up with all of these disadvantages just to use the old iMac in TDM.
Thankyou.
So I’ll need to downgrade to Catalina. Do I need to erase my disk before I install it? I’ve read I should download Catalina to a usb and boot from that.
Cannot use 2011 Mac as external display for 2017 MacBook Air
